The location of the Trailing Thermal Control Radiator (TTCR) on the outboard truss on the port-side of the space station. After its retraction, both of P-6’s 2B and 4B power channels will be routed through the main Photovoltaic Radiator (PVR). Image Credit: NASA

Expedition 45 spacewalker Kjell Lindgren works to restore the P-6 cooling system to its pre-2012 configuration during U.S. EVA-33 in November 2015. He and Scott Kelly ultimately left the Trailing Thermal Control Radiator (TTCR) fully deployed when the crew ran out of time and encountered other difficulties. Photo Credit: NASA

Pictured during an earlier excursion, Sunita Williams became the world’s most experienced female spacewalker at the end of US EVA-20. She now ranks fifth in the world, with more than 50 hours in seven EVAs and is surpassed only by Anatoli Solovyov, Mike Lopez-Alegria, Jerry Ross and John Grunsfeld. Photo Credit: NASA